Much development work has been done in connection with delivering fuel to internal combustion engines, in particular in recent years, the delivery of combustible fuel and gas, especially air, in metered quantities. Much of the work has centered around the delivery of a fuel mixture to two-cycle, spark ignition engines. U.S. Pat. No. 4,693,224 (Sep. 15, 1987) and U.S. Pat. No. 4,825,828 (May 2, 1989) illustrate and describe the problems of fuel injection and the advantages of direct in-cylinder injection which is effective in operation, economic to manufacture and achieves and maintains acceptable atomization of the fuel.
The present invention is specifically directed to internal combustion engines where a premetered quantity of fuel is entrained in a gas, conveniently air, and the fuel entrained in the gas is delivered directly into the combustion chamber of the engine through a nozzle which is intermittently opened. In one form this is achieved by the use of a poppet valve which is controlled and moved axially to open and closed positions using an electromagnetic coil and an armature closely associated with the poppet valve. Each cylinder, in a multi-cylinder engine, is provided with a fuel and air nozzle injection assembly.
As described in the above-referenced patents, the poppet valve has a cone-type configuration at the delivery end which influences the spray pattern of the injected fuel. The flow is axially along the outside of the poppet valve and is directed into a cylinder in a spray pattern by the conical surface at the delivery end. In the invention to be described, a standard fuel injection valve is utilized in connection with an air mixing element such that the mixture of fuel and air is delivered to the poppet valve for timed injection directly into an engine cylinder.
The features of the present invention involve a mounting of the poppet valve to an armature within the electromagnetic solenoid assembly to insure concentricity and squareness, and also a proper connection which will withstand the rapid reciprocation of the valve.
Another feature of the invention is the shape and contour of the poppet valve at the discharge end to avoid accumulation of unwanted residue which would interfere with proper operation.
Still another feature is the provision of a one-piece molded mixing insert which is positioned at the juncture of the incoming fuel, from a fuel injector, and the incoming air prior to the dual mixture traveling to the timed poppet and thence to the engine cylinder.
Additional objects and features of the invention will be apparent in the following description and claims in which the principles of the invention are set forth together with details to enable persons skilled in the art to practice the invention, all in connection with the best mode presently contemplated for the invention.